We don't respond to individual crash reports. They are aggregate by crash type and then the top occurring ones are pursued for fixes. We then contact people if we need additional information to solve the crash.

Switching shouldn't crash obviously. Does it still crash if you first quit QuickBooks?  Note that holding down the option key when launching QuickBooks will prevent it from defaulting to opening the last used company file.

Let me know here if that works. Either way, lets talk through what is happening here and since it is occurring so frequently for you we may be able to fix an outstanding bug.  Are you on QuickBooks Mac 2015?